This invention relates to the art of fluid handling, particularly to a valve having three ports controlled by a spring-biased spool which is mechanically displaced by inserting a syringe tip into one of the ports.
When liquids are being administered to a patient from a I.V. bag or the like via a catheter, it may sometimes be desired to administer a secondary medication through the catheter. This can be done by providing the catheter conduit with an injection port, into which a syringe can be inserted. When materials are injected into the conduit from the syringe, however, they will naturally follow the path of least resistance, which in some cases may be toward the I.V. bag. It would therefore be possible to contaminate or taint the contents of the bag, if some means were not provided for preventing reverse flow. It is therefore customary to provide a check valve between the injection site and the bag.
Another consideration is that an injection port, if permanently installed in the catheter conduit, must not leak, or admit unintended materials.